The present invention describes a process for the solubilization of a hydrocarbon liquid into an aqueous solution of a sulfonated diblock polymer of t-butylstyrene/metal styrene sulfonate or a triblock polymer of t-butylstyrene/metal styrene sulfonate/t-butylstyrene, wherein the incorporation of the hydrocarbon liquid causes an increase in the viscosity of the aqueous liquid.
Water soluble diblock polymers of t-butylstyrene/metal styrene sulfonate or triblock polymers of t-butylstyrene/metal styrene sulfonate/t-butylstyrene of relatively low molecular weight, have been found to efficiently viscosify water. These polymers have a water soluble block and a hydrocarbon soluble block. For aqueous solubility, the water soluble block is greater than 80 weight percent of the total polymer. One method of preparing the block polymers is to anionically polymerize a hydrocarbon soluble block polymer. This is followed by the selective functionalization of the major block to render said block water soluble. The functionalization in this invention is sulfonation of the resulting sulfonic acid. These block polymers readily dissolve in water. The resulting solutions exhibit enhanced viscosity at low concentrations (i.e., 500 to 1500 ppm) relative to solutions of homopolymers of even higher molecular weight. They also have viscosity levels significantly greater than corresponding random copolymer solutions of similar compositions.
Numerous U.S. Patents have taught methods of sulfonating a variety of elastomeric and thermoplastic polymers. These U.S. Patents are: U.S. Pat. Nos. 3,642,728; 3,836,511; 3,072,618; 3,072,619; 3,847,854; 3,870,841 and 3,877,530. However, none of these references teach the process for preparing the sulfonated diblock and triblock polymers of the instant invention, nor do they recognize that sulfonated polymers of this class are excellent oil solubilization agents for aqueous solutions, wherein the incorporation of the oil causes an increase in the viscosity of the aqueous solution.